Fuel-air metering and induction system

Abstract

A fuel-air metering and induction system for an internal combustion engine including an electronic controlled pressurized carburetion system wherein a carburetor mounted on top of the intake manifold of an internal combustion engine is provided with one or more throttle valves to regulate the flow of induction fluid therethrough with a mass airflow meter including an air metering valve mounted on a shaft for rotation in the induction passage positioned upstream thereof, the air metering valve shaft having a cam thereon to actuate the metering rod of a fuel metering valve to control the delivery of fuel to a fuel atomizing nozzle discharging fuel into the induction stream immediately downstream of the throttle valves, the fuel metering valve being supplied with high pressure fuel from an electrically controlled, high pressure fuel pump, the output pressure and therefore volume of fuel delivered to the fuel metering valve being regulated as a function of electrical signals received which are indicative of various engine operating conditions and the mass airflow through the mass airflow meter.

What is claimed is: 
     
       1. A fuel-air supply system for an engine having an air induction passage means provided with a flow control throttle valve, said fuel and air supply system including a mass airflow meter assembly in communication with the air induction passage upstream of the throttle valve and having a pivotable air valve and a servo mechanism operably connected to the air valve and operable as a function of the differential air pressure across said air valve to maintain said differential air pressure substantially constant under all engine operating conditions to essentially effect airflow measurement, a fuel supply means including a fuel pump for supplying high pressure fuel, a fuel atomizing nozzle positioned for discharge into the air induction passage means downstream of the throttle valve, said fuel atomizing nozzle being supplied with air from the air induction passage upstream of the throttle valve and being supplied with fuel from said fuel supply means, an electrically controlled valve mechanism and a fuel metering valve connected in series between said fuel supply means and said fuel atomizing nozzle, said fuel metering valve being operatively connected to said air valve whereby fuel flow through said fuel metering valve is varied as a function of the rotative position of said air valve and, electric circuit means for supplying an electrical signal to said electrically controlled valve mechanism, said electric circuit means having variable means responsive to airflow through said airfow metering means, to a plurality of engine operating conditions and to the differential fuel pressure across said fuel metering valve for controlling the magnitude of said electrical signal. 
     
     
       2. A fuel-air supply system according to claim 1 wherein said fuel pump is a variable displacement pump having a slider movable in a pump housing relative to a pump rotor rotatably journaled in the pump housing for varying the output displacement of said pump, and wherein said electrically controlled valve mechanism is operatively connected to said pump housing whereby to supply fuel at a controlled pressure to said pump housing on one side of said slider to effect movement of said slider as a function of the electrical signal supplied by said electric circuit means. 
     
     
       3. A fuel-air metering and induction system for an internal combustion engine having an intake manifold with an induction passage therein including an air induction means in communication with the induction passage with flow therethrough controlled by at least one throttle valve, a mass airflow metering assembly in communication with the air induction means upstream of said throttle valve, said mass airflow metering assembly including an air valve pivotably positioned in the cylindrical bore of a valve housing having contoured holes of continuous profile, but inverted with respect to each other, and extending from opposite sides of the valve housing to run out at the crossbore, and a servo mechanism operable as a function of the differential air pressure across said air valve to move said air valve to maintain said differential air pressure substantially constant under all engine operating conditions, a fuel supply means including a fuel pump for supplying high pressure fuel, a fuel atomizing nozzle positioned for discharge into the air induction passage means downstream of the throttle valve, said fuel atomizing nozzle being supplied with air from the air induction passage upstream of the throttle valve and being operatively connected to said fuel supply means, an electrically controlled valve mechanism and a fuel metering valve means connected in series between said fuel supply means and said fuel atomizing nozzle, said fuel metering valve being operatively connected to said air valve whereby fuel flow through said meter is varied as a function of the rotative position of said air valve and, electric circuit means for supplying an electrical signal to said electrically controlled valve mechanism, said electric circuit means having variable means responsive to airflow through said airflow metering means, to a plurality of engine operating conditions and to the differential fuel pressure across said fuel metering valve for controlling the magnitude of said electrical signal. 
     
     
       4. A fuel-air metering and induction system for an internal combustion engine having an intake manifold with an induction passage therein, including an air induction means havig an air induction passage therethrough in communication with the induction passage with airflow through said air induction passage controlled by at least one throttle valve, a mass airflow meter including an air metering valve mounted on a rotatable valve shaft positioned upstream of said air induction means, an electrically controlled variable displacement fuel pump having an inlet connected to a source of fuel and having an outlet, a fuel meter having an inlet connected to said outlet of said electrically controlled variable displacement fuel pump and having an outlet, an air atomizing fuel nozzle positioned for discharge into said induction passage downstream of said throttle valve and having a fuel inlet connected to said outlet of said fuel meter, said fuel meter being operatively connected to said air metering valve whereby fuel flow through said fuel meter is varied as a function of the rotative position of said air metering valve, an electronic computer controller operatively connected to said electrically controlled fuel pump to provide an electrical signal thereto for controlling the output volume and pressure of fuel from said electrically controlled fuel pump, engine sensor means responsive to engine operating conditions to produce electrical signals responsive to engine operating conditions, an air-fuel ratio programmer electrically connected to said engine sensor means and providing an electrical output signal to said electronic computer controller in accordance with signals received from said engine sensor means, an air meter sensor means operatively connected to said air meter valve to sense the pressure drop across said air meter valve and the temperature and pressure of air flowing through said air meter valve to provide corresponding electrical output signals to said electronic computer controller and, sensing means to sense the differential fuel pressure across said fuel meter to provide an electrical comparative input signal to said electronic computer controller. 
     
     
       5. A fuel-air metering and induction system for an internal combustion engine having an intake manifold with an induction passage therein, a carburetor housing means having an induction passage therethrough mounted on the engine manifold with its induction passage in communication with the induction passage of said engine manifold, at least one throttle valve pivotably mounted in said induction passage of said carburetor housing for controlling the flow of induction fluid therethrough, a mass airflow meter including an air metering valve rotatably mounted on a pivotable metering valve shaft in a contoured induction passage means upstream of said throttle valve, a fuel reservoir, a fuel pump having an inlet operatively connected to said fuel reservoir and an outlet, an electrically controlled variable displacement fuel pump having an inlet connected to said outlet of said fuel pump and an outlet, a fuel meter having an inlet connected to said outlet of said electrically controlled variable displacement fuel pump and an outlet, an air atomizing fuel nozzle positioned for discharge into said induction passage downstream of said throttle valve and having its fuel inlet connected to said outlet of said fuel meter, said fuel meter having an orifice passage between its inlet and said outlet and a tapered metering rod movably positioned relative to said orifice to control the flow therethrough, a cam on said air meter valve shaft positioned to actuate said tapered metering rod in one direction relative to said orifice and spring means operatively connected to said tapered metering rod to normally bias said metering rod in the opposite direction, an electronic control operatively connected to said electrically controlled fuel pump to provide an electrical signal to control the output volume and pressure of fuel from said electrically controlled fuel pump, engine sensor means to sense engine operating conditions and to provide electrical signals corresponding to the engine operating conditions, an air-fuel ratio programmer electrically connected to said engine sensor means and providing an electrical output signal to said electronic computer controller, an air meter sensor means operatively connected to said air meter valve to sense the pressure drop across said air meter valve and the temperature and pressure of air flowing through said air meter valve and to provide corresponding electrical signals, said air meter sensor means being electrically connected to said electronic computer controller and, sensing means to sense the pressure differential across said fuel meter to provide an electrical input signal to said electronic computer controller. 
     
     
       6. A fuel-air metering and induction system according to claim 5 wherein said carburetor housing means includes a throttle plate having a central aperture for supporting said air atomizing fuel nozzle for discharge downstream of said throttle valve and on opposite sides of said central aperture a pair of outlet passages, a pair of throttle shafts journalled in parallel, spaced apart relation to each other in said throttle plate in position to rotatably support a pair of throttle valves for controlling flow through said passages, gear means connected to said throttle shafts in engagement with each other to effect synchronized, but opposed, rotation of said throttle valves with the rotation of said throttle valves being such as to direct the flow of air through said passages in a direction toward the output of said air atomizing fuel nozzle.